const readline = require("readline");
const ytdl = require("ytdl-core");
const ffmpeg = require("fluent-ffmpeg");
const id3 = require('node-id3');
const axios = require('axios');
var request = require("request").defaults({ encoding: null });
const chalk = require('chalk');

/**
 * log function for logging in one shell line.
 * @param something the thing that should be logged.
*/
const log = (something) => {
  readline.clearLine(process.stdout, 0);
  readline.cursorTo(process.stdout, 0);
  process.stdout.write(something);
}

const convertTime = (timeString /* '00:00:46.27' */) => {
  const timeParts = timeString.split(':');
  let seconds = Number(timeParts[2]);
  seconds = seconds + (Number(timeParts[1]) * 60) + (Number(timeParts[0]) * 60 * 60);
  return seconds;
};

if (process.argv.length !== 5) {
  console.log(chalk.red('Not getting metadata for this song!'));
}

ffmpeg.setFfmpegPath(__dirname + '/ffmpeg');

log(chalk.yellow("ℹ️　Getting information from YouTube..."));

ytdl.getInfo(process.argv[2], (err, info) => {
  let stream = ytdl(process.argv[2], {
    quality: "highestaudio"
    //filter: 'audioonly',
  });

  const path = `${__dirname}/music/${info.title}.mp3`;

  log(chalk.yellow("🏁　Starting download..."));

  ffmpeg(stream)
    .audioBitrate(128)
    .save(path)
    .on("progress", p => {
      const progress = convertTime(p.timemark);
      log(
        chalk.blue(
          `⬇️　${Math.floor(
            (progress / Number(info.length_seconds)) * 100
          )}% downloaded.`
        )
      );
    })
    .on('error', err => {
      log(chalk.red('Error: ' + err.message))
      process.exit();
    })
    .on("end", () => {
      if (process.argv.length === 5) {
        // Retreiving info from itunes api and writing tags to downloaded file.
      const artist = process.argv[3];
      const song = process.argv[4];

      log(chalk.yellow("🎵　Calling iTunes api..."));

      axios.get(`https://itunes.apple.com/search?term=${artist} ${song}&entity=song`).then(res => {
        request.get(res.data.results[0].artworkUrl100, function(err, _res, body) {

          log(chalk.green("✅　Retreived information!"));

          var tags = {
            title: song,
            artist: res.data.results[0].artistName,
            album: res.data.results[0].collectionName,
            image: {
              mime: "jpeg",
              type: {
                id: 3,
                name: "front cover"
              },
              imageBuffer: body
            },
            date: res.data.results[0].releaseDate,
            fileType: "mp3",
            genre: res.data.results[0].primaryGenreName
          };

          log(chalk.yellow("✍🏻　Writing tags to mp3 file..."));

          id3.update(tags, path);

          log(chalk.green(`✅　Successfully downloaded ${info.title}.mp3!\n`));

          process.exit();
        });
      });
    } else {
      log(chalk.green(`✅　Successfully downloaded ${info.title}.mp3!`));

      process.exit();
    }
  });
});